The present invention relates to a vehicle navigation system and method, which use mobile communication between a vehicle into which a navigation apparatus is installed and a base station so as to communicate route information for guiding the vehicle, thereby guiding the vehicle.
In a vehicle navigation system in the past, the current position of the vehicle and its target destination are communicated to a base station using a mobile communication apparatus, a recommended route to its target destination is searched at the base station based on the acquired current position, and this recommended route data is transmitted to the vehicle.
According to an investigation made by the present inventors, in a vehicle navigation system of the past, because only a recommended route is transmitted to the vehicle, there can occur discrepancies between the display screen and the actual road, so that it is possible to veer from the recommended route and follow the deviated road.
As a countermeasure with respect to the above-noted problem, a system can be envisioned in which, in addition to the recommended route from the base station, road map data is also transmitted from the base station.
In the above-noted case, however, because of the limitations in circuit capacity normally imposed on mobile communication, the time required for transmission becomes long, and also there can be interruptions of the circuit during the transmission. In the case in which the circuit is interrupted during communication, it is necessary to restart the series of data to be transmitted from the beginning, this representing a drop in communication efficiency.
Accordingly, the present invention was made in consideration of the above-noted drawbacks, and has as an object to provide a vehicle navigation system and method which seek to improve the faithfulness of the display screen with respect to the actual road, and which also provide an improvement in communication efficiency.
A vehicle navigation system according to the present invention comprises a navigation apparatus transmitting a current position of a vehicle and a target destination of the vehicle, and a base station receiving the current position and the target destination, searching a route information from the current position to the target destination, and transmitting the route information to the navigation apparatus. The base station includes an information storage section storing map information and added information with regard to road features, a route searching section searching the added route information from the information storage section, a transmitting section transmitting the route information to the navigation apparatus and then transmitting the added information to the navigation apparatus. The navigation apparatus displays the route information and the added route information each of which is transmitted from the base station.
According to the above-noted configuration, the map information and also added information which represents, for example, visible features of the road are pre-stored at the base station, and a search is made as to the added information which relates to the selected route. The route information is transmitted to the navigation apparatus, and then the added information is transmitted to the navigation apparatus. At the navigation apparatus, the route information and also added information received from the base station are displayed.
Therefore, the operator such as a passenger can view not only the route information, but also the added information that represents visible road features regarding the selected route, thereby improving the faithfulness of the display to the actual road being traveled. As a result, it is possible to effectively prevent the operator from veering from the selected route and traveling along the different road.
Stated in different terms, a vehicle navigation system according to the present invention comprises a navigation apparatus transmitting a current position of a vehicle and a target destination of the vehicle, and a base station receiving the current position and the target destination, searching a route information from the current position to the target destination, and transmitting the route information to the navigation apparatus. The base station includes means for storing added information with regard to road features, means for searching the added route information from the storage means and means for transmitting the route information to the navigation apparatus and for then transmitting the added route information to the navigation apparatus. The navigation apparatus displaying the route information and the added route information each of which is transmitted from the base station.
On the other hand, in a vehicle navigation method according to the present invention, a navigation apparatus transmits a current position of a vehicle and a target destination of the vehicle to a base station, and the base station receives the current position and the target destination. At the base station, route information with regard to a route from the current position to the target destination is searched, and the route information is transmitted to the navigation apparatus. Besides, the added route information with regard to the route is searched, and after the route information is transmitted to the navigation apparatus, the added route information is transmitted to the navigation apparatus. The navigation apparatus displays the route information and added route information each of which is transmitted from the base station.